The present invention relates to a film scanning device for capturing images formed on a photographing film.
Recently, in association with widespread use of personal computers, images captured by digital still cameras and/or scanned by scanners are often processed by the personal computers. In order to make use of images photographed with photographing films (i.e., images formed on silver-salt films), a film scanner has been developed and used.
An example of a film scanner is provided with a sensor such as a CCD (Charge Coupled Device) line sensor. By the CCD line sensor, an image on the photographing film is scanned in one direction (i.e., in a principal scanning direction), and by moving the CCD line sensor relative to the image in a direction perpendicular to the principal scanning direction (i.e., in an auxiliary scanning direction), the electronic image can be obtained (i.e., the image is scanned and image data corresponding to the scanned image is generated).
In such a film scanner, in order to scan the image accurately, a pre-scanning may be performed generally before a normal, or a main-scanning is performed. The pre-scanning is performed to check the orientation, position and the like of the image to be scanned, while the main-scanning is performed to obtain the image data. In view of the purpose, the pre-scanning need not be performed at high resolution. Further, it is preferable that the pre-scanning is performed at relatively a high speed, and a pre-view image is provided immediately for a user of the film scanner.
In the conventional film scanner, when the pre-scanning is performed, the number of auxiliary scanning operations is reduced by performing the principal scanning operation only at every predetermined number of auxiliary scanning pitch. In such a system, however, the moving speed of the line sensor with respect to the image is unchanged even if the pre-scanning is performed, and only the quantity of data is different. Therefore, the scanning period is substantially the same regardless whether the pre-scanning or main scanning is performed.